1. Field of the Invention
This invention relates to an improved safety box toe for use in shoes and the like and relates more particularly to a relatively rigid stiffener or insert element formed in the toe area of a shoe to provide protection for the wearer.
It should be understood that although the following discussion will be directed primarily to incorporation of a safety box toe according to this invention into a shoe, the same inventive concepts relate to other types of footwear such as boots and the like.
2. Description of the Prior Art
Numerous prior art safety box toe designs have been developed heretofore primarily intended to protect the toes of the wearer against injury caused by external forces that come into contact with the toe portion of a shoe. Current standards of performance for safety footwear are described in the American National Standard Z-41.1-1967(R 1972), which is incorporated herein in its entirety by reference.
To define performance two types of force application are considered, namely impact and compression type forces. The former tends to simulate the resultant force of a falling object, while the latter simulates any relatively slow-moving object. The standard also recognizes that different industrial situations create different degrees of hazards. Three classes of hazards are defined in the standard as follows:
REQUIREMENTS FOR CLASS IMPACT COMPRESSION ______________________________________ 30 30 ft-lbs. 1,000 lbs. 50 50 ft-lbs. 1,750 lbs. 75 75 ft-lbs. 2,500 lbs. ______________________________________
The standard specifies that any particular design or model must comply with both the impact and compression requirements for the given class while maintaining a minimum clearance under the safety toe box of one-half inch.
The conventional safety box toe shapes for safety footwear are designed to conform to the forward portion of the safety footwear last. All safety footwear are made over lasts which are a reproduction of the approximate shape of the human foot. The box toe are flanged to allow the box toe to conform to the last and to wrap around the last featherline, insole and lining if used, as a method of securing the safety box toe in the footwear. In conventionally designed safety box toes the flange is uniform in width and narrow providing a uniform horizontally projected area. This narrow uniform distribution of the projected area allows the safety box toe to rotate rearwardly under external forces resulting in a reduction of the toe clearance and also allowing a tendency for the flange edges to cut through the supporting soling materials.
In certain designs of safety box toes the flanges have been extended over the entire bottom portion of the box toe element or, alternatively, have been extended to form a strap-like element adjacent the rear edge of the box toe element. Such designs have produced a "guillotine" effect by clamping the toes of the wearer between the bottom element or strap and the upper portion of the safety box toe upon the application of an external force resulting in increased injury and great difficulty in removing the safety toe from the foot after impact.
While certain modifications of conventional box toe elements have resulted in non-uniform flange means, no recognition has been given heretofore to the tendency of a safety box toe to rotate rearwardly under the application of external forces, nor are any of the prior art designs presently available capable of overcoming this tendency.
Another difficulty with many prior art safety box toes is the tendency for the element to spread after application of a load, thereby again reducing the toe clearance upon impact or compression.